In the field of alphanumeric video displays, an "attribute" is a modifiable aspect of a displayed character, such as blinking, intensified, reverse video, underlined, and protected against overwriting.
The prior art has been oriented toward utilizing holding buffers in conjunction with current-attribute buffers for storing an attribute code or codes until called for. This type of software programming and hardware architecture has not provided for any program control as the operation is predetermined. The prior art with considerable brute-force techniques would allow for underlining characters or striking out characters, various types of formatting of material in a text, and any of the other attributes as performed in the prior art operations.
The prior art required that the old attribute had to be respecified at the end of the field, which required considerable storage for attributes as previously utilized. Further, there was considerable software searching the data to find the last valid attribute, which not only required additional storage, but also required additional time, both of the storage hardware and software searching time leading to inefficient data processing.
The present invention overcomes the disadvantages of the prior art by providing hardware assist controlled by software reducing the number of bytes for levels of attributes and commands to control the attribute levels.